Cross Made: 4/15/05
Ploidy Verified: 2/18/08
We are very proud to announce the confirmation of our first tetraploid Phal. equestris var cyanochilus. This is an exciting confirmation that we have the ability to convert diploids to tetraploids along with the technology to do the chromosome counts in our own lab. These 4n equestris var cyanochilus have turned out to be superior to their 2n sibblings with larger flowers with wider segements, a very wide lip and much darker lip color.
diploids (2n) - with 38 chromosomes is the natural ploidy of Phalaenopsis
tetraploids (4n) - have a chromosome count of 76 and have better form and increased size.
This tetraploid was created by treating seedlings with colchicine while still in the protocorm stage. We have a number of other coerulea crosses that we are converting to polyploids and will be using these in our blue breeding program.
This is a photo with the 2n (diploid) on the left and our new 4n (tetraploid) on the right.
The form has improved considerably as well as noticable
increase in the size of the petals, sepals and lip.
Guard Cell Measurements
Taken on 7/10/07
Guard cells on the bottom side of the leaf from potential tetraploids are measured and compared to the guard cells of knowm diploids. The area of the guard cell of a tetraploid is usually twice that of a similiar diploid. By measuring guard cells, potential conversions can be isolated so the large populations do not need to be chromosome counted.
Measurement from a known diploid equestris var cyanochilus
Measurement from the potential tetraploid equestris var cyanochilus. You cna see from the measurements that the guard cells are more than double the size of the cells from the known diploid. This was indication that this plant was likely tetraploid and it was worth spending the extra time to do a chromosome count to veriofy the ploidy.
Photo's of the official chromosome count showing 76 chromosomes
Taken 2/18/08 at 1600X magnification:
These are the photo's of the chromosome count from the tetraploid equestris above.
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